There is known an image display sheet in which an image can be observed as a virtual image such as moving, changing and like with movement, or movement and deformation, by utilizing visual sense of an observer. The image display sheet is composed of a lenticular sheet which is constituted by an arrangement of a plurality of cylindrical lenses and an image forming layer.
FIGS. 26A and 26B are views for explaining a conventionally known image display sheet, in which FIG. 26A is a perspective view explaining a basic characteristic of a lenticular, and FIG. 26B is an illustrated view for explaining a basic principle of the lenticular.
A lenticular sheet 5001 is composed of cylindrical lenses 5002 and an image forming layer 5003 disposed on a surface opposite to a surface formed so as to provide a convex shape so that an image can be observed from a lens side in a pseudo-dynamic manner. In an arrangement, in shape of stripe, of an image 5004 for a right eye of an observer and an image 5005 for a left eye of the observer, a changing image in which an image is observed as if it moves by changing viewing angles of the observer (right eye and left eye of the observer 5006 and 5007).
FIG. 27 is for explaining a conventionally known image display sheet 5009, in which (A) is a view for explaining a section of a conventionally known image sheet 5009, and (B) is a plan view of the image forming layer 5003. On the image forming layer 5003 formed to an image forming medium 5008, a plurality of original picture A, B, C, D are divided into stripe shape. FIG. 27 is an example in which the image for right eye 5004 and the image for left eye 5005 are divided each at predetermined width with respect to the respective lenses. When moving a line of sight (visual line of an observer), an A-image is observed at a certain position, a B-image is observed at another certain position, a C-image is observed at a further certain position, and a D-image is observed at a further certain position, as if the image is moved by changing the viewing (observing) angles of an observer.
Further, the Patent Document 1 discloses a technology in which when a plurality of original images are divided into stripe shape to form one sheet of images so as to create images which are observed as if they have different pictures as viewed from different viewing angles, boundary of a pitch of a convex lens and divided boundary of the image is made coincident with each other.
In the meantime, the Patent Document 2 discloses a technology in which an image for right eye of an observer and an image for left eye of the observer are divided into strip-shaped pieces each having a predetermined width with respect to each lens, and then, by arranging the divided pieces in interlace shape, a pseudo variable image is observed.